I feel your pain.

However I don't think that moving the datacenter to an EU location is going to solve this problem specifically.

Many of us in the US, even those in Canada who are right in the datacenter's back yard are having issues with brutal lag spikes and disconnections, leaving the game barely playable. If you hunt around in the forums a bit you can see the many, many posts about it.

To be honest, 99% of the lag complaints I've read on here are in not from EU players, and the severe lag is generally not caused by any specific distance from FFXIV servers.